<?php
namespace TYPO3\CMS\Version\Dependency;

/**
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */

use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Backend\Utility\BackendUtility;
use TYPO3\CMS\Core\Versioning\VersionState;

/**
 * Processor having generic callback methods for element entities
 */
class ElementEntityProcessor {

	/**
	 * @var int
	 */
	protected $workspace;

	/**
	 * @var \TYPO3\CMS\Core\DataHandling\DataHandler
	 */
	protected $dataHandler;

	/**
	 * Sets the current workspace.
	 *
	 * @param int $workspace
	 */
	public function setWorkspace($workspace) {
		$this->workspace = (int)$workspace;
	}

	/**
	 * Gets the current workspace.
	 *
	 * @return int
	 */
	public function getWorkspace() {
		return $this->workspace;
	}

	/**
	 * @return \TYPO3\CMS\Core\DataHandling\DataHandler
	 */
	public function getDataHandler() {
		if (!isset($this->dataHandler)) {
			$this->dataHandler = GeneralUtility::makeInstance('TYPO3\\CMS\\Core\\DataHandling\\DataHandler');
		}
		return $this->dataHandler;
	}

	/**
	 * Transforms dependent elements to use the liveId as array key.
	 *
	 * @param array|ElementEntity[] $elements
	 * @return array
	 */
	public function transformDependentElementsToUseLiveId(array $elements) {
		$transformedElements = array();
		/** @var $element ElementEntity */
		foreach ($elements as $element) {
			$elementName = ElementEntity::getIdentifier($element->getTable(), $element->getDataValue('liveId'));
			$transformedElements[$elementName] = $element;
		}
		return $transformedElements;
	}

	/**
	 * Callback to determine whether a new child reference shall be considered in the dependency resolver utility.
	 *
	 * @param array $callerArguments
	 * @param array $targetArgument
	 * @param ElementEntity $caller
	 * @param string $eventName
	 * @return NULL|string Skip response (if required)
	 */
	public function createNewDependentElementChildReferenceCallback(array $callerArguments, array $targetArgument, ElementEntity $caller, $eventName) {
		$fieldConfiguration = BackendUtility::getTcaFieldConfiguration($caller->getTable(), $callerArguments['field']);
		if (!$fieldConfiguration || !GeneralUtility::inList('field,list', $this->getDataHandler()->getInlineFieldType($fieldConfiguration))) {
			return ElementEntity::RESPONSE_Skip;
		}
		return NULL;
	}

	/**
	 * Callback to determine whether a new parent reference shall be considered in the dependency resolver utility.
	 *
	 * @param array $callerArguments
	 * @param array $targetArgument
	 * @param \TYPO3\CMS\Version\Dependency\ElementEntity $caller
	 * @param string $eventName
	 * @return NULL|string Skip response (if required)
	 */
	public function createNewDependentElementParentReferenceCallback(array $callerArguments, array $targetArgument, ElementEntity $caller, $eventName) {
		$fieldConfiguration = BackendUtility::getTcaFieldConfiguration($callerArguments['table'], $callerArguments['field']);
		if (!$fieldConfiguration || !GeneralUtility::inList('field,list', $this->getDataHandler()->getInlineFieldType($fieldConfiguration))) {
			return ElementEntity::RESPONSE_Skip;
		}
		return NULL;
	}

	/**
	 * Callback to determine whether a new child reference shall be considered in the dependency resolver utility.
	 * Only elements that are a delete placeholder are considered.
	 *
	 * @param array $callerArguments
	 * @param array $targetArgument
	 * @param ElementEntity $caller
	 * @param string $eventName
	 * @return NULL|string Skip response (if required)
	 */
	public function createClearDependentElementChildReferenceCallback(array $callerArguments, array $targetArgument, ElementEntity $caller, $eventName) {
		$response = $this->createNewDependentElementChildReferenceCallback($callerArguments, $targetArgument, $caller, $eventName);
		if (empty($response)) {
			$record = BackendUtility::getRecord($callerArguments['table'], $callerArguments['id']);
			if (!VersionState::cast($record['t3ver_state'])->equals(VersionState::DELETE_PLACEHOLDER)) {
				$response = ElementEntity::RESPONSE_Skip;
			}
		}
		return $response;
	}

	/**
	 * Callback to determine whether a new parent reference shall be considered in the dependency resolver utility.
	 * Only elements that are a delete placeholder are considered.
	 *
	 * @param array $callerArguments
	 * @param array $targetArgument
	 * @param ElementEntity $caller
	 * @param string $eventName
	 * @return NULL|string Skip response (if required)
	 */
	public function createClearDependentElementParentReferenceCallback(array $callerArguments, array $targetArgument, ElementEntity $caller, $eventName) {
		$response = $this->createNewDependentElementParentReferenceCallback($callerArguments, $targetArgument, $caller, $eventName);
		if (empty($response)) {
			$record = BackendUtility::getRecord($callerArguments['table'], $callerArguments['id']);
			if (!VersionState::cast($record['t3ver_state'])->equals(VersionState::DELETE_PLACEHOLDER)) {
				$response = ElementEntity::RESPONSE_Skip;
			}
		}
		return $response;
	}

	/**
	 * Callback to add additional data to new elements created in the dependency resolver utility.
	 *
	 * @throws \RuntimeException
	 * @param ElementEntity $caller
	 * @param array $callerArguments
	 * @param array $targetArgument
	 * @param string $eventName
	 * @return void
	 */
	public function createNewDependentElementCallback(array $callerArguments, array $targetArgument, ElementEntity $caller, $eventName) {
		$versionRecord = $caller->getRecord();
		// If version record does not exist, it probably has been deleted (cleared from workspace), this means,
		// that the reference index still has an old reference pointer, which is "fine" for deleted parents
		if (empty($versionRecord)) {
			throw new \RuntimeException(
				'Element "' . $caller::getIdentifier($caller->getTable(), $caller->getId()) . '" does not exist',
				1393960943
			);
		}
		// If version is on live workspace, but the pid is negative, mark the record as invalid.
		// This happens if a change has been discarded (clearWSID) - it will be removed from the command map.
		if ((int)$versionRecord['t3ver_wsid'] === 0 && (int)$versionRecord['pid'] === -1) {
			$caller->setDataValue('liveId', $caller->getId());
			$caller->setInvalid(TRUE);
			return;
		}
		if ($caller->hasDataValue('liveId') === FALSE) {
			// Set the original uid from the version record
			if (!empty($versionRecord['t3ver_oid']) && (int)$versionRecord['pid'] === -1 && (int)$versionRecord['t3ver_wsid'] === $this->getWorkspace()) {
				$caller->setDataValue('liveId', $versionRecord['t3ver_oid']);
			// The current version record is actually a live record or an accordant placeholder for live
			} elseif ((int)$versionRecord['t3ver_wsid'] === 0 || (int)$versionRecord['pid'] !== -1) {
				$caller->setDataValue('liveId', $caller->getId());
				$versionRecord = BackendUtility::getWorkspaceVersionOfRecord(
					$this->getWorkspace(),
					$caller->getTable(),
					$caller->getId(),
					'uid,t3ver_state'
				);
				// Set version uid to caller, most likely it's a delete placeholder
				// for a child record that is not recognized in the reference index
				if (!empty($versionRecord['uid'])) {
					$caller->setId($versionRecord['uid']);
				// If no version could be determined, mark record as invalid
				// (thus, it will be removed from the command map)
				} else {
					$caller->setInvalid(TRUE);
				}
			// In case of an unexpected record state, mark the record as invalid
			} else {
				$caller->setInvalid(TRUE);
			}
		}
	}

}
